<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0px;
            padding: 0px;
        }
        div.outer{
            width: 1090px;
            height: 380px;
            margin: 0 auto;
            /* border: 1px solid red; */
        }
        div.outer>div{
            float:left;
        }
        div.outer>div.left{
            width: 690px;
            height: 380px;
            /* border: 1px solid blue; */
            background-color: red;
            margin-right: 10px;
        }
        div.outer>div.right{
            width: 390px;
            height: 380px;
            /* border: 1px solid blue; */
        }
        .top:first-child{
            margin-bottom: 10px;
        }
        .top{
            width: 390px;
            height: 185px;
            background-color: green;
        }
        .bottom{
            width: 390px;
            height: 185px;
            background:blue;
        }
    </style>
</head>
<body>
    <div class="outer">
        <div class="left"></div>
        <div class="right">
            <div class="top"></div>
            <div class="bottom"></div>
        </div>
    </div>
</body>
</html>